Microscopic examination of biopsy material is an essential component of many diagnostic procedures. There are many different biopsy techniques. Many biopsy procedures are performed in an operating room setting with the patient under anesthesia. A biopsy is often performed to confirm a diagnosis and, as soon as the finding from the biopsy is received, and the original diagnosis is confirmed, the practitioner performs a surgical procedure. Generally, the biopsy sample is transmitted to a lab where the tissue sample is sectioned, stained and microscopically examined. Since in many cases, the patient is already under anesthesia, any time spent transporting the biopsy specimen to a remote laboratory, subjects the patient to additional risk associated with prolonged anesthesia.
Biopsy techniques may be divided into closed and open methods. Closed techniques include aspiration (for cysts), aspiration for cytology (for suspected carcinoma) and core biopsy for histology. Open techniques include incisional biopsy, excisional biopsy and needle localization biopsy. Lung biopsy is often performed with a bronchoscope and a grasper or a brush is used to obtain the sample of the target tissue. A technique now being used more frequently is the Fine Needle Aspiration Biopsy. Many of these biopsy techniques only yield a small sample of tissue.
Once the tissue sample is obtained, it must be prepared for evaluation. One commonly used technique requires the sample to be frozen, sectioned on a microtome, stained and microscopically evaluated. The freezing and sectioning procedures are time consuming. Tissue samples also are fixed in formalin, embedded in paraffin and sectioned on a microtome. Fixation in formalin and embedding in paraffin requires a fume hood as formalin is considered toxic and is strongly irritating to mucous membranes. In another commonly practiced technique, the tissue sample may be partially digested with enzymes to free cells from the connective tissue for microscopic evaluation.
Sample preparation and evaluation practices vary from institution to institution. In many cases, practitioners who would otherwise prefer to have rapid evaluation of a biopsy specimen conducted as part of the biopsy procedure, are required to transmit the sample to a remote laboratory for evaluation because an enzymatic digestion of the sample to provide free cells is required. The transmission to the laboratory is required because the enzymatic work-up requires laboratory facilities to prepare the enzyme solution in a suitable medium. If a system were available that included appropriate amounts of enzyme and a suitable medium for the enzymatic dissociation of the cells from the connective tissue, the art of rapid evaluation of a biopsy sample would be advanced. Such a device and a method for its use are described herein below.